Corn – improving pollination

All types of corn are pollinated by breezes that blow pollen from the male flowers onto the silk threads that emerge from the top of each ear of corn. This is why it is better for home gardeners to grow corn in a block rather than a long row. Each strand of silk is connected to a separate immature seed and is covered in tiny sticky hairs that collect the pollen. If some silk strands don’t receive pollen, kernels may not form along one side of a cob, or near the top of the cob. (Female part of corn plant in photo at left.)

Male flowers form at the top of the corn plant as an upright spike and lower branches that open out like umbrella spokes. Pollen forms in small yellow ovals (anthers) that release their pollen mid morning after dew has dried from the flowers (between about 9 and 11 am). The centre spike is the first part to release its pollen. Pollen release may only last from 3 to 5 days and the released pollen is only viable for up to 24 hours. (Male flower in photo at left.)
It can help when growing small quantities of sweet corn or popcorn to pollinate it by hand, to ensure that the cobs your plants produce are full of juicy kernels. In nature, silks are rarely pollinated by the same plant.

To ensure good pollination, you need a sheet of A4 paper and a clean, dry, soft paintbrush. Fold the paper in half lengthways and open it out, then fold it in half the opposite way and open it out. This helps the paper to form a shallow well. Or, you can use a small clean shallow tray – something easy to manoeuvre between the plants. Hold the paper under a male flower and gently tap the spike and lower branches of the male flower with the handle of the paint brush. When tassels are ready to be pollinated, plenty of bright yellow pollen will fall onto the paper. Collect some of the pollen on the hairs of the paintbrush and dab it onto all sides and the centre of silk strands of other corn plants. Repeat this process over several days. Once a tassel has been pollinated, the ends of the silk strands will start to turn brown. As the cobs mature, you may have to net your corn crop as birds know when corn is perfect for eating.
Corn anthers won’t release pollen when conditions are too wet or very dry, the plants will wait until conditions are favourable. In areas of Australia that experience long periods of rain, it is best to plan your corn crop to avoid the wet season.

Bees welcome

Beelvdr2 Although we do not use pesticides, in recent years we have noticed fewer bees in our garden. In response we have set up a hive under a white mulberry tree, and added a ‘bee garden’ in a corner of our vege patch. I’ve planted a short hedge of French Lavender (Lavandula dentata) that flowers from late autumn to mid spring, when few other flowers bloom. I’ve also added some Borage (Borago officinalis) as a treat for bees, and some Manuka shrubs (Leptospermum scoparium) to add its healing benefits to our honey.
The decline in bee numbers has become a global problem, with the United States losing  45 per cent of their bees and Europe has 13 million less bee colonies. It is a very serious problem because many of the foods we eat depend on bee pollination to produce crops or seed. If bee numbers continue to decline you can forget about having honey, the cost of manual pollination of crops would be exorbitant and many foods will become a luxury (See list below). Colony Collapse Disorder is the most puzzling aspect of this decline, where bees leave their hives and just disappear over winter.
In the past, CCD has been blamed on diseases, mites, poor nutrition, or Manuka Shrubpesticides, particularly the neurotoxic neonicotinoids. Last year, research at Harvard University found that long exposure to small amounts of two neonicotinoids (imidacloprid and clothianidin) are the likely cause of CCD. The European Union has already banned the use of three neonicotinoids, Unfortunately, Australia, that lags behind Europe in environmental issues, still allows the use of these pesticides.

TO ENCOURAGE BEES TO YOUR GARDEN:

Borage They need clean water, pollen and nectar. Keep a shallow container of clean water (e.g. birdbath) in your garden, and choose shrubs and annuals that flower in different months to provide a continuous supply of pollen and nectar. Both native bees and honey bees love our native shrubs. And, don’t use pesticides that harm bees. Read labels and Material Safety Data Sheets (MSDS) carefully before use. Your garden will benefit greatly from the presence of these tiny, hard-working creatures.

Common foods that need bees to produce, fruits, nuts, vegetables and seed
Apple, Apricot, Blueberry, Boysenberry, Cherry, All Citrus, Cranberry, Cucumber, Currants, Custard Apple, Elderberry, Feijoa, Gooseberry, Grapes, Guavas, Kiwifruit, Melons, Nectarine, Papaya, Passionfruit, Pawpaw, Peach, Pear, Persimmon, Plum, Pomegranate, Quince, Raspberry, Starfruit, Strawberry, Almond, Brazil, Cashew, Chestnut, Coconut, Hazelnut, Macadamia, Walnut, Marrows, Okra, Pumpkin, Squash, Zucchini.
Common foods that need bees to produce seed
Beetroot, Broad bean, Broccoli, Brussels sprouts, Buckwheat, Cabbages, Canola, Caraway, Carrot, Cauliflower, Celery, Chinese vegetables, Clover, Coriander, Cotton, Cowpea, Dill, Fennel, Linseed, Lucerne, Mustard, Nasturtium, Onions, Parsley, Parsnip, Pigeon pea, Radish, Rocket, Scarlet runner, Sesame, Silverbeet, Turnip.

http://www.businessinsider.com.au/harvard-study-links-pesticides-to-colony-collapse-disorder-2014-5
http://www.theguardian.com/environment/2014/jan/08/uk-food-security-honeybees